My mother has been on contract with Virgin for 6years and ever since she switched from PAYG to pay monthly she has never been able to use her phone(s) abroad.
She is currently in Malta with again no signal only thing is she is now in hospital and being able to use her phone has become more of a necessity rather than a luxury.
everytime she calls Virgin before she leaves to ensure she will be able to use her phone and everytime she gets on holiday ....nothing the phone does not find the network.
This time she even went into the local store and they said everything was set up on both the billing and the technical side... I think the service is shocking I have never had a problem with my Vodafone mobile so why should VM find it so hard to make a number work abroad.
It difficult to pin this down, I take it you are with your mum? If so check international roaming is set on the phone, then switch off and on, go into settings and networks do a manual network selection, if it finds a local network select that and see it it works then. If your mum has set up a Virgin Web account have a look and see if it shows that roaming is active